Astronomers intrigued by a ‘radically different’ solar system


(journalist)
– In some solar systems, including ours, the planets orbit around the equator of the star. In others, they orbit around the poles of the star – and in the one that puzzled astronomers, both types of orbit were observed. The researchers say that in the HD 3167 system about 150 light years away, the innermost planet, HD 3167 b, has an orbit like the planets in our system but the two outer ones, HD 3167 c and d, have a polar orbit perpendicular to that of HD 3167b, the New York Times reports. In a study published in the journal Astronomy & Astrophysicsthe researchers say the odd mix of orbits may be the result of “interactions with an outside companion” – a Jupiter-sized planet they haven’t yet observed, or some other unknown force.

“It’s something radically different from our own solar system,” said lead researcher Vincent Bourrier from the University of Geneva. Times. He says that if you were on a planet with a telescope “and you looked at the trajectory of the other planets in the system, they would go vertically across the sky.” IFLScience notes that the system’s planets “look pretty ordinary” despite their unusual orbits: HB 3167b is classified as a “super-Earth,” about five times the size of our planet, while the outer two resemble Neptune. All three are considered too close to the system’s star, an orange dwarf, for there to be any possibility of life. Bourrier says the discovery, the first of its kind, shows “planets can evolve in really, really different ways.” (Read more exoplanet stories.)

Arline J. Mercier